NASA's Cassini spacecraft has found two new, partial rings around Saturn that each accompany a small moon, shedding light on what determines whether a partial or complete ring forms with the moon.

The partial rings, called ring arcs, extend ahead of and behind the small Saturnian moons Anthe and Methone in their orbits.

Both Anthe and Methone orbit Saturn in locations called resonances, where the gravity of the nearby larger moon Mimas disturbs their orbits. Mimas provides a regular gravitational tug on each moon, which causes the moons to skip forward and backward within an arc-shaped region along their orbital paths, said Nick Cooper of Queen Mary, University of London an a member of the Cassini imaging team.

"When we realized that the Anthe and Methone ring arcs were very similar in appearance to the region in which the moons swing back and forth in their orbits due to their resonance with Mimas, we knew we had a possible cause-and-effect relationship," Cooper said.

Scientists believe that the faint ring arcs likely consist of material knocked off the small moons by micrometeoroid impacts. The material doesn't spread all the way around Saturn to form a complete ring because the interactions of the moons with Mimas confine the material to a narrow region along the moons' orbits.

The recent Cassini images were the first detection of arc material near Anthe. The images confirmed the presence of the Methone arc, which was previously detected by Cassini's Magnetospheric Imaging Instrument.

Previous Cassini images have also shown faint rings connected with other small moons within or near the outskirts of Saturn's main ring system, such as Pan, Janus, Epimetheus and Pallene. Cassini has also previously observed an arc in the G ring, one of Saturn's fain, major rings.

"This is probably the same mechanism responsible for producing the arc in the G ring," said Matthew Hedman of Cornell University and another Cassini imaging team member.

Hedman and his colleagues previously determined that the G-ring arc is also formed by gravitational resonance with Mimas.

"Indeed, the Anthe arc may be similar to the debris we see in the G-ring arc, where the largest particles are clearly visible," Hedman said. "One might even speculate that if Anthe were shattered, its debris might form a structure much like the G ring."

The material that orbits with Pallene, Janus and Epimetheus, however, isn't subject to the same powerful resonant forces and is free to spread out around the planet, forming a complete ring.

If you only knew the magnificence of the 3, 6 and 9, then you would have a key to the universe.— Nikola TeslaCasting Out the Nines from PHI into Indigs reveals the Cosmic Harmonic Code.— Junglelord.Knowledge is Structured in Consciouness. Structure and Function Cannot Be Seperated.— Junglelord

Saturn’s rings may be more massive than previously thought, and potentially much older, according to calculations that simulate colliding particles in Saturn’s rings and their erosion by meteorites. These results support the possibility that Saturn’s rings formed billions of years ago, perhaps at the time when giant impacts excavated the great basins on the Moon. The findings also suggest that giant exoplanets may also commonly have rings.

Esposito’s colleagues at the University of Colorado, Glen Stewart and Stuart Robbins, have computed the gravitational attraction and collisions between more than 100,000 particles, representing a sample of those in Saturn’s rings. They followed the orbit and history of each individual particle, and calculate the amount of starlight that would pass through the ring. These results have been compared to Cassini observations of starlight blocked by the rings, which has traditionally been used to estimate the total amount of material in the ring system. Esposito used this method in 1983 to estimate that rings of Saturn contain as much material as Saturn’s small moon Mimas, which is about 250 miles across. The new simulations show Saturn’s ring particles aggregate into clumps, which would lead to the previous estimate being low by a factor of 3 or more.

Because the rings appear so clean and bright, it was argued that the rings of Saturn were much younger than Saturn, which is some 4.5 billion years old. It was calculated from Voyager measurements that the rings are only about 100 million years old, approximately as ancient as when dinosaurs inhabited the Earth. The new calculations show that if the rings are more massive, they appear less polluted, and thus could be proportionately older. Recycling of ring material extends their lifetime and reduces the expected darkening.

One problem with this proposal for more massive and ancient rings is that the Pioneer 11 space mission to Saturn in 1979 measured the ring mass indirectly by observing charged particles created by cosmic rays bombarding the rings.

“Those mass estimates were similar to the ones from Voyager star occultations, apparently confirming the previous low mass value. However, we now recognize that the charged particles are double-valued. That means they could arise from either a small or large mass. We now see that the larger mass value could be consistent with the underestimates due to ring clumpiness,” said Dr Esposito.

So they first make calculations doing only gravity and later on they acknowledge chargedness of particles. Did they ever hear of dusty plasma? Probably not.

The illusion from which we are seeking to extricate ourselves is not that constituted by the realm of space and time, but that which comes from failing to know that realm from the standpoint of a higher vision. -L.H.

Observations from NASA’s Cassini spacecraft have been used to build, for the first time, a 3-D picture of the sources of intense radio emissions in Saturn’s magnetic field, known as the Saturn Kilometric Radiation (SKR).

The results will be presented by Dr Baptiste Cecconi, of LESIA, Observatoire de Paris, at the European Planetary Science Congress on Tuesday 23rd September.

The SKR radio emissions are generated by high-energy electrons spiralling around magnetic field lines threaded through Saturn’s auroras. Previous Cassini observations have shown that the SKR is closely correlated with the intensity of Saturn’s UV aurora and the pressure of the solar wind.The measurements were made using Cassini’s Radio and Plasma Wave Science (RPWS) experiment. http://www.lesia.obspm.fr/~cecconi/files/EPSC-SKR-movie.mp4“The animation shows radio sources clustered around curving magnetic field lines. Because the radio signals are beamed out from the source in a cone-shape, we can only detect the sources as Cassini flies through the cone. When Cassini flies at high altitudes over the ring planes, we see the sources clearly clustered around one or two field lines. However, at low latitudes we get more refraction and so the sources appear to be scattered,” said Dr Cecconi.

The model found that the active magnetic field lines could be traced back to near-polar latitudes degrees in both the northern and southern hemisphere. This matches well with the location of Saturn’s UV aurora. Although there were some minor differences between emissions in the northern and southern hemispheres, the emissions were strongest in the western part of Saturn’s sunlit hemisphere. This area corresponds to a region of Saturn’s magnetopause where electrons are thought to be accelerated by the interaction of the solar wind and Saturn’s magnetic field.

The illusion from which we are seeking to extricate ourselves is not that constituted by the realm of space and time, but that which comes from failing to know that realm from the standpoint of a higher vision. -L.H.

This is a side-by-side view of large cyclones at both poles of Saturn obtained by the visual and infrared mapping spectrometer onboard the Cassini spacecraft.At both poles, the discrete, circular and oblong clouds dotting the image are likely convective upwelling originating deep inside the planet, which help to power the cyclones. These views show clouds throughout the atmosphere, down to as deep as 125 kilometers (78 miles) below the haze. Many of the features seen are thought to be deep-level clouds of ammonia-hydrosulfide, which form at these levels and rise to higher altitudes in convective updrafts.Normally, Saturn’s internal glow illuminates Saturn’s deep clouds from below, thus rendering the clouds in silhouette against this background glow. In these images, the contrast has been reversed so as to make the clouds appear more like they would look if seen in reflected sunlight. The original images obtained by infrared spectrometer show the clouds as dark features against the internal glow. The grid shows planeticentric latitudes. In this polar orthographic projection, 0 degrees longitude is toward the top, 90 degrees west longitude to the right, etc, based on the longitude system established by Voyager.

The entire north pole of Saturn is now mapped in detail in infrared, with features as small as 120 kilometers (75 miles) visible in the images. Time-lapse movies of the clouds circling the north pole show the whirlpool-like cyclone there is rotating at 530 kilometers per hour (325 miles per hour), more than twice as fast as the highest winds measured in cyclonic features on Earth. This cyclone is surrounded by an odd, honeycombed-shaped hexagon, which itself does not seem to move while the clouds within it whip around at high speeds, also greater than 500 kilometers per hour (300 miles per hour). Oddly, neither the fast-moving clouds inside the hexagon nor this new cyclone seem to disrupt the six-sided hexagon.

Complementary images of the south pole from Cassini’s imaging cameras, obtained in mid-July, are 10 times more detailed than any seen before. "What looked like puffy clouds in lower resolution images are turning out to be deep convective structures seen through the atmospheric haze," said Cassini imaging team member Tony DelGenio of NASA’s Goddard Institute for Space Studies in New York. "One of them has punched through to a higher altitude and created its own little vortex."

The "eye" of the vortex is surrounded by an outer ring of high clouds. The new images also hint at an inner ring of clouds about half the diameter of the main ring, and so the actual clear "eye" region is smaller than it appears in earlier low-resolution images.

"It’s like seeing into the eye of a hurricane," said Andrew Ingersoll, a member of Cassini's imaging team at the California Institute of Technology, Pasadena. "It’s surprising. Convection is an important part of the planet’s energy budget because the warm upwelling air carries heat from the interior. In a terrestrial hurricane, the convection occurs in the eyewall; the eye is a region of downwelling. Here convection seems to occur in the eye as well."

Thanks again Cassini ! Great movies too. Though the article itself is again an example of missing the obvious.

The illusion from which we are seeking to extricate ourselves is not that constituted by the realm of space and time, but that which comes from failing to know that realm from the standpoint of a higher vision. -L.H.

The hexagon may very well be the geometry of the nucleus.viewtopic.php?f=8&t=1083Its an amazing demonstration of geometry and natural processes that could be fractal from the nucleus to the carbon ring to the Saturn polar configuration seen here.

If you only knew the magnificence of the 3, 6 and 9, then you would have a key to the universe.— Nikola TeslaCasting Out the Nines from PHI into Indigs reveals the Cosmic Harmonic Code.— Junglelord.Knowledge is Structured in Consciouness. Structure and Function Cannot Be Seperated.— Junglelord

The unusual phenomenon in question involves rotating a bottom plate under a liquid in a circular (cylindrical) container. Bohr and his team of students at the Technical University and at the Niels Bohr Institute set up an experiment to find out whether or not such conditions would lead to stable deformations of a water surface into polygon shapes. The findings from their experiment were published May 3rd in Physical Review Letters.

“We had fluid falling on a plane, like water from a faucet. We found that even if the rim of the plate is completely circular, the fluid surface can be shaped like a polygon.”

While the first polygon experiment Bohr did involved stationary polygons, the most recent effort shows rotating polygons. “Not only are these shapes rotating,” says Bohr, “but they are rotating at a different speed than the plate beneath them.”

Bohr finds the mystery fascinating. The circle shape demonstrates instability, but when it develops into a polygon (and Bohr’s team has found that the polygon can have anywhere from two to six sides), it becomes quite stable and can remain the same for hours. In some cases there can also be slow transitions from one polygon to another.

But then again, I suppose, at Saturn other things are "falling" down and up??

The illusion from which we are seeking to extricate ourselves is not that constituted by the realm of space and time, but that which comes from failing to know that realm from the standpoint of a higher vision. -L.H.

Its clearly a soliton, a non linear coherent structure.The institute for non linear science should give them a call.

If you only knew the magnificence of the 3, 6 and 9, then you would have a key to the universe.— Nikola TeslaCasting Out the Nines from PHI into Indigs reveals the Cosmic Harmonic Code.— Junglelord.Knowledge is Structured in Consciouness. Structure and Function Cannot Be Seperated.— Junglelord

Simple relationship...sixth planet, six sided hexagon. Follow history, see how saturn and the influence of both planet and geometry on peoples minds in the past is linked!

If you only knew the magnificence of the 3, 6 and 9, then you would have a key to the universe.— Nikola TeslaCasting Out the Nines from PHI into Indigs reveals the Cosmic Harmonic Code.— Junglelord.Knowledge is Structured in Consciouness. Structure and Function Cannot Be Seperated.— Junglelord

An inexplicable new broad region of auroral light has been photographed at Saturn's polar cap.

"We've never seen an aurora like this elsewhere," said Tom Stallard, an RCUK Academic Fellow working with Cassini data at the University of Leicester. "It's not just a ring of aurorae like those we've seen at Jupiter or Earth. This one covers an enormous area across the pole. Our current ideas on what forms Saturn's aurorae predict that this region should be empty, so finding such a bright one here is a fantastic surprise."

These colorful atmospheric light shows are caused when charged particles stream along the magnetic field of a planet and into its atmosphere. On Earth the charged particles come from the solar wind – a stream of particles that emanates from the sun. Skywatchers at high latitudes know the resulting displays as the Northern Lights.

Jupiter's main auroral ring, caused by interactions internal to Jupiter's magnetic environment, is constant in size. Saturn's main aurora, which is caused by the solar wind, changes size dramatically as the wind varies.

The newly observed aurora at Saturn, however, doesn't fit into either category.

"Saturn's unique auroral features are telling us there is something special and unforeseen about this planet's magnetosphere and the way it interacts with the solar wind and the planet's atmosphere," said Nick Achilleos, a scientist on the Cassini magnetometer team at the University College London. "Trying to explain its origin will no doubt lead us to physics which uniquely operates in the environment of Saturn."

The new image, in infrared, was imaged by the Cassini spacecraft. It is reported in the Nov. 13 issue of the journal Nature.

MartianSam wrote:Saturn is unique in that the magnetic and geographic poles are almost perfectly aligned. It's also unique in having such a large volume and low density with a relatively tame magnetic field as a whole. I suspect that between the two there may be something strange happening with localized magnetic loops or twists in the upper atmosphere around the poles.In other words, with Earth and Jupiter, I suspect that the aurora would, due to the daily cycle of angles against the solar wind, would tend to form a ring where the forces balanced out over time and the peaks and troughs would cancel each other out. With Saturn, there may be more time for "noise" to accumulate and be expressed as well as the main ring.